A technique is presented whereby a marker map can be constructed using reso
urce family data with an entire class of missing data. The focus is on a ha
lf-sib design where there is only information on a single parent and its pr
ogeny. A Bayesian approach is utilised with solutions obtained via a Markov
chain Monte Carlo algorithm. Features of the approach include the capacity
to determine parameters for the ungenotyped dam population, the ability to
incorporate published information and its reliability, and the production
of posterior densities and the consequent deduction of a wide range of infe
rences. These features are demonstrated through the analysis of simulated a
nd experimental data.